L'évaluation des effectifs de la population des pays africains : vol. 2

Dans la conclusion de l'ouvrage sur "L'évaluation des effectifs de la population des pays africains", les auteurs mettent en perspective le contenu des 44 monographies pour en tirer des conclusions relatives à l'amélioration des méthodes de collecte et d'analyse. Dans la première partie, les auteurs dressent un bilan des sources de données (estimations anciennes, recensements administratifs, autres sources administratives, recensements statistiques, enquêtes post-censitaires, enquêtes par sondages), puis dans la deuxième partie, ils procèdent à l'étude critique des sources en examinant successivement le champ géographique, la population de référence, les problèmes posés par certaines catégories de population et les facteurs susceptibles d'avoir une influence sur la qualité de la collecte. La troisième partie est consacrée à l'analyse de la cohérence des données, en fonction du type et de la qualité des données disponibles. Enfin en conclusion sont présentés les effectifs proposés dans les monographies pour la population des pays revue au 1er janvier 1975, et sont rassemblées des propositions d'amélioration des sources de donnée

Durability of Therapeutic Response to Milnacipran Treatment for Fibromyalgia. Results of a Randomized, Double-Blind, Monotherapy 6-Month Extension Study

To evaluate the durability of improvement and long-term efficacy of milnacipran treatment in fibromyalgia, to assess efficacy in patients re-randomized from placebo to milnacipran, and to collect additional information on the tolerability and efficacy of long-term treatment with milnacipran.A total of 449 patients who successfully completed a 6-month lead-in study enrolled in this 6-month extension study (87.7% of eligible subjects). Patients initially receiving milnacipran 200 mg/day during the lead-in study were maintained at 200 mg/day (n = 209); patients initially assigned to placebo or milnacipran 100 mg/day were re-randomized (1:4) to either 100 mg/day (n = 48) or 200 mg/day (n = 192) of milnacipran for an additional 6 months of treatment. Efficacy assessments included visual analog scale pain ratings, Fibromyalgia Impact Questionnaire (FIQ) total score, and Patient Global Impression of Change (PGIC).Patients continuing on milnacipran demonstrated a sustained reduction in pain over the full 12-month period. Additional beneficial effects were also maintained, as indicated by the PGIC and FIQ. Patients initially assigned to either placebo or milnacipran 100 mg/day in the lead-in study and subsequently re-randomized to milnacipran 200 mg/day in the extension study experienced further improvements in their mean pain scores, FIQ total scores, and PGIC ratings at 1 year. Milnacipran treatment was generally well tolerated. The most commonly reported newly emergent adverse event was nausea.In addition to confirming that milnacipran safely and effectively improves the multiple symptoms of fibromyalgia, these data indicate that milnacipran provides 1-year durable efficacy in this patient population.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78636/1/j.1526-4637.2009.00755.x.pd

Absolute measurement of the unresolved cosmic X-ray background in the 0.5-8 keV band with Chandra

We present the absolute measurement of the unresolved 0.5-8 keV cosmic X-ray background (CXB) in the Chandra Deep Fields (CDFs) North and South, the longest observations with Chandra (2 Ms and 1 Ms, respectively). We measure the unresolved CXB intensity by extracting spectra of the sky, removing all point and extended sources detected in the CDF. To model and subtract the instrumental background, we use observations obtained with ACIS in stowed position, not exposed to the sky. The unresolved signal in the 0.5-1 keV band is dominated by diffuse Galactic and local thermal-like emission. In the 1-8 keV band, the unresolved spectrum is adequately described by a power law with a photon index 1.5. We find unresolved CXB intensities of (1.04+/-0.14)x10^-12 ergs cm^-2 s^-1 deg^-2 for the 1-2 keV band and (3.4+/-1.7)x10^-12 ergs cm^-2 s^-1 deg^-2 for the 2-8 keV band. Our detected unresolved intensities in these bands significantly exceed the expected flux from sources below the CDF detection limits, if one extrapolates the logN/logS curve to zero flux. Thus these background intensities imply either a genuine diffuse component, or a steepening of the logN/logS curve at low fluxes, most significantly for energies <2 keV. Adding the unresolved intensity to the total contribution from sources detected in these fields and wider-field surveys, we obtain a total intensity of the extragalactic CXB of (4.6+/-0.3)x10^-12 ergs cm^-2 s^-1 deg^-2 for 1-2 keV and (1.7+/-0.2)x10^-11 ergs cm^-2 s^-1 deg^-2 for 2-8 keV. These totals correspond to a CXB power law normalization (for photon index 1.4) of 10.9 photons cm^-2 s^-1 keV^-1 sr^-1 at 1 keV. This corresponds to resolved fracations of 77+/-3% and 80+/-8% for 1-2 and 2-8 keV, respectively.Comment: 23 emulateapj pages, accepted for publication in ApJ. Minor revisions, most notably a new summary of the error analysi

De l'homme au chiffre. Réflexions sur l'observation démographique en Afrique

Ce manuel aborde de façon concrète les problèmes posés par la collecte des données démographiques à partir de l'expérience des praticiens du domaine. La définition des concepts et les problèmes linguistiques sont envisagés. Les phases de réalisation d'une opération sont examinées à travers l'organisation du travail sur le terrain, la cartographie, l'exploitation des données et l'archivage des documents. La dernière partie présente les méthodes de collecte particulières à certains thèmes (fécondité, mortalité, migrations, emploi et activité

The X-ray surface brightness distribution from diffuse gas

We use simulations to predict the X-ray surface brightness distribution arising from hot, cosmologically distributed diffuse gas. The distribution is computed for two bands: 0.5-2 keV and 0.1-0.4 keV, using a cosmological-constant dominated cosmology that fits many other observations. We examine a number of numerical issues such as resolution, simulation volume and pixel size and show that the predicted mean background is sensitive to resolution such that higher resolution systematically increases the mean predicted background. Although this means that we can compute only lower bounds to the predicted level, these bounds are already quite restrictive. Since the observed extra-galactic X-ray background is mostly accounted for by compact sources, the amount of the observed background attributable to diffuse gas is tightly constrained. We show that without physical processes in addition to those included in the simulations (such as radiative cooling or non-gravitational heating), both bands exceed observational limits. In order to examine the effect of non-gravitational heating we explore a simple modeling of energy injection and show that substantial amounts of heating are required (i.e. 5 keV per particle when averaged over all baryons). Finally, we also compute the distribution of surface brightness on the sky and show that it has a well-resolved characteristic shape. This shape is substantially modified by non-gravitational heating and can be used as a probe of such energy injection.Comment: 11 pages, 11 figures, submitted to Ap

The deepest X-ray look at the Universe

The origin of the X-ray background, in particular at hard (2-10 keV) energies, has been a debated issue for more than 30 years. The Chandra deep fields provide the deepest look at the X-ray sky and are the best dataset to study the X-ray background. We searched the Chandra Deep Field South for X-ray sources with the aid of a dedicated wavelet-based algorithm. We are able to reconstruct the Log N-Log S source distribution in the soft (0.5-2 keV) and hard (2-10 keV) bands down to limiting fluxes of 2x10^{-17} erg s^{-1} cm^{-2} and 2x10^{-16} erg s^{-1} cm^{-2}, respectively. These are a factor ~5 deeper than previous investigations. We find that the soft relation continues along the extrapolation from higher fluxes, almost completely accounting for the soft X-ray background. On the contrary, the hard distribution shows a flattening below ~2x10^{-14} erg s^{-1} cm^{-2}. Nevertheless, we can account for >68% of the hard X-ray background, with the main uncertainty being the sky flux itself.Comment: Accepted for publication on ApJL. Two figures, requires emulateapj5 (included

The resolved fraction of the Cosmic X-ray Background

We present the X-ray source number counts in two energy bands (0.5-2 and 2-10 keV) from a very large source sample: we combine data of six different surveys, both shallow wide field and deep pencil beam, performed with three different satellites (ROSAT, Chandra and XMM-Newton). The sample covers with good statistics the largest possible flux range so far: [2.4*10^-17 - 10^-11] cgs in the soft band and [2.1*10^-16 - 8*10^{-12}]cgs in the hard band. Integrating the flux distributions over this range and taking into account the (small) contribution of the brightest sources we derive the flux density generated by discrete sources in both bands. After a critical review of the literature values of the total Cosmic X--Ray Background (CXB) we conclude that, with the present data, the 94.3%, and 88.8% of the soft and hard CXB can be ascribed to discrete source emission. If we extrapolate the analytical form of the Log N--Log S distribution beyond the flux limit of our catalog in the soft band we find that the flux from discrete sources at ~3*10^-18 cgs is consistent with the entire CXB, whereas in the hard band it accounts for only 93% of the total CXB at most, hinting for a faint and obscured population to arise at even fainter fluxes.Comment: Accepted for publication in Ap

“These Trees Have Stories to Tell”: Linking Dënesǫ́łıné Oral History of Caribou Use with Trample Scar Frequency on Black Spruce Roots at Ɂedacho Kué

For thousands of years Ɂedacho Kué (Artillery Lake, Northwest Territories) has been a key water crossing site for barren-ground caribou (Rangifer tarandus groenlandicus). Human disturbance of barren-ground caribou habitat in northern Canada has emerged as an important focus of study in the last decade; particularly in the Bathurst range of the Northwest Territories where caribou populations have declined by more than 95% since the 1980s. Guided by local Indigenous leaders and Elders, a collaborative research project was developed with the Dënesǫ́łıné people of Łutsël K’e Dëne First Nation (2012 – 14). This paper describes linkages between knowledge derived from Dënesǫ́łıné oral history and quantitative dendroecological analysis of trample scars on black spruce (Picea mariana) root samples collected at Ɂedacho Kué to provide a better understanding of caribou use at this location. Findings from oral histories and dendroecology analysis were consistent with one another and with previous dendroecology study in the region, although some discrepancies were detected in data from 1995 – 2006 that require further study to elucidate. Key findings include relatively low caribou use at Ɂedacho Kué during the 1930s and late 1960s, with use increasing into the 1970s and peaking in the late 1980s, as well as Elder and hunter reports of no caribou in some years between 2005 and 2012. This work addresses a gap in scientific data about barren-ground caribou movements at Ɂedacho Kué prior to satellite collar use in 1996 and corroborates previously documented oral histories about the enduring value of Ɂedacho Kué as critical habitat to barren-ground caribou. Given the drastic decline of the Bathurst caribou over the last two decades, more research is needed to understand movements and their relationship to population dynamics. In this context, the research approach described in this paper could be used as an example of how to meaningfully bring together place-based Indigenous knowledge and science in addressing an urgent issue of Arctic sustainability.    Depuis des milliers d’années, Ɂedacho Kué (lac Artillery, Territoires du Nord-Ouest) sert d’important point de franchissement de cours d’eau pour le caribou de la toundra (Rangifer tarandus groenlandicus). La perturbation anthropique de l’habitat du caribou de la toundra dans le Nord canadien a fait l’objet d’études importantes ces dix dernières années, plus particulièrement dans l’aire de répartition de Bathurst, dans les Territoires du Nord-Ouest, où les populations de caribous ont chuté de plus de 95 % depuis les années 1980. Un projet de recherche collaborative guidé par des chefs et des aînés autochtones locaux a été conçu en consultation avec le peuple Dënesǫ́łıné de la Première Nation Łutsël K’e Dëne (2012 – 2014). Cet article décrit les liens entre les connaissances dérivées de l’histoire orale des Dënesǫ́łınés et l’analyse dendroécologique quantitative des cicatrices de piétinement se trouvant sur les échantillons de racines d’épinettes noires (Picea mariana) prélevés à Ɂedacho Kué afin de mieux comprendre l’utilisation de ce lieu par les caribous. Les constatations découlant de l’histoire orale et de l’analyse dendroécologique concordaient ensemble ainsi qu’avec une étude dendroécologique antérieure de la région, bien que certains écarts aient été décelés dans les données de 1995 à 2006, écarts qui se doivent d’être étudiés afin d’être élucidés. Parmi les principales constatations, notons l’utilisation relativement faible de Ɂedacho Kué par les caribous pendant les années 1930 et la fin des années 1960, une utilisation accrue dans les années 1970 ayant atteint un sommet vers la fin des années 1980, ainsi que le signalement de l’absence de caribous par les aînés et les chasseurs au cours de certaines années entre 2005 et 2012. Notre recherche comble un manque de données scientifiques relativement aux déplacements du caribou de la toundra à Ɂedacho Kué avant que les colliers émetteurs à transmission par satellite ne commencent à être employés en 1996. Elle corrobore l’histoire orale documentée précédemment au sujet de la valeur durable de ?edacho Kué en tant qu’habitat critique du caribou de la toundra. En raison de la chute importante de la population du caribou de Bathurst ces deux dernières décennies, de plus amples recherches s’imposent afin de comprendre les déplacements et leur lien avec la dynamique de la population. Dans ce contexte, la démarche de recherche décrite dans cet article pourrait servir d’exemple montrant comment concilier les connaissances autochtones d’un endroit avec la science pour faire face à un enjeu urgent de durabilité de l’Arctique.

What can BeppoSAX do about the 2-10 keV cosmic background ? A progress report

We report the current status of the analysis of the MECS background using the entire dataset of the BeppoSAX Science performance Verification Phase. We have collected 360 ks of dark Earth instrumental background, 470 ks of bright Earth background and 1100 ks of blank field data. We are attempting to model the instrumental background in terms of its various components (in particular the spatial modulation of the residual contamination by the built-in Fe calibration sources), and then use this model, and the information on the vignetting and the PSF to derive the cosmic background in the 2-10 keV rangeComment: 8 pages, 9 figures imbedded, To appear in The Active X-ray Sky: Results from BeppoSAX and Rossi-XTE, Nuclear Physics B Proceedings Supplements, L. Scarsi, H. Bradt, P. Giommi and F. Fiore (eds.), Elsevier Science B.